This week, I am inaugurating the GRHYD project (Management of Networks through the Injection of Hydrogen) in the urban community of Dunkirk, where, for the first time in France, renewable hydrogen will be injected into the local gas distribution network to meet the heating and hot water needs of citizens.

Far from being isolated cases, these projects are signs heralding a transformation in the energy system towards a 100% renewable world.

The energy revolution is not a smooth progression. It is a movement comprised of shifts and phases where things speed up followed, sometimes, by slower progress.

The first shift came from the competitiveness of renewable energy, which triggered the switch towards new sources of energy. Thus, in 2016, for the first time, investment in renewable energy overtook investment in hydrocarbons.

However, we have now reached a plateau. Continuing the deployment of proven technological solutions on a larger scale is not enough to overcome two major problems that stand in the way of a 100% renewable world.

The first is the intermittent production of renewable energies. The problem is a familiar one. The production of renewable energies is variable, discontinuous and cannot be scheduled. It depends first and foremost on uncontrollable weather conditions, such as sunlight or the wind.

Combined with this, we do not yet know how to store this electricity in large quantities for long periods of time. Electric batteries can cover short-term needs, but how can we cover seasonal variations and use the solar energy produced in the summer, to cover needs in the winter?

The second problem is decarbonisation of all energy uses: transport, heating and industrial processes. Let us take the example of transport. It is 95% dependent on oil and the transportation sector is responsible for 23% of CO2 emissions worldwide. What fuels should be adopted? Should we focus all our efforts on electric vehicles, even though this would require huge investment? Consider that the size of the electricity grid of Beijing would have to be doubled simply to convert 10% of the fleet to electricity.

Where will the technological shift which will enable us to leap ahead to the next stage of the energy (r)evolution come from?

My reply is in one word: hydrogen, the missing link for a completely decarbonised world.

I am speaking here of renewable hydrogen, produced by the electrolysis of water which uses electricity of renewable origin (Power-to-Gas).

First of all, hydrogen solves the problem of how to deal with intermittent renewable energy. Indeed, Power-to-Gas is currently the best solution for storing renewable energy on a large scale. Renewable electricity surpluses are used to produce hydrogen which can then be directly injected into the gas network (Power-to-Gas) or be converted into electricity via a fuel cell (Power-to-Gas-to-Power or Power-to-Power).

Used as an alternative or supplement to electric batteries, hydrogen thus makes the energy system more resilient. Power-to-Gas moreover has the advantage of using gas infrastructure that has already been paid-for and it becomes part of a circular economy system, where renewable electricity surpluses will be systematically transformed and reused.

ENGIE is already developing several pilot projects around the world to test out these Power-to-Gas and Power-to-Power technologies.

There is the first Power-to-Gas demonstrator in France, the GRHYD project.

There is also the micro-network that we are developing on the island of Semakau, off the coast of Singapore, and which is based on solar energy, wind energy, a battery and a “hydrogen brick”. Hydrogen is the key element, which can be used to store surplus energy and smooth the intermittent supply. This 100% renewable micro-network provides a very promising avenue for the electrification of rural and isolated areas.

Hydrogen also allows several energy uses to be decarbonised such as transport and industrial processes.

We are still in the early stages of the development of the electric hydrogen hybrid vehicle sector. However, for certain types of vehicles (buses, taxis, delivery vehicles) this sector is particularly relevant to meet the increasingly demanding air pollution regulations.

These are electric vehicles whose power is stored in the form of pressurised hydrogen. The electricity is produced in real time on board the vehicle by combining hydrogen and oxygen in a fuel cell. Electric hydrogen vehicles only emit water vapour, are silent, have a range 2 to 3 times greater than battery electric vehicles and can be refuelled in 5 minutes in equipped stations.

The last example of decarbonisation is that of certain industrial processes that use a lot of hydrogen such as ammonia production and refining. Indeed, the grey hydrogen used by these industries is produced by a process that emits a lot of CO2, natural gas cracking. For every kilogram of hydrogen produced, 10 kilograms of CO2 are thus emitted.

There is a very strong development potential in this market: 85% of the 60 million tons of hydrogen produced worldwide in 2013 was used for ammonia production and petrochemicals.

Replacing this grey hydrogen with renewable hydrogen would thus significantly reduce CO2 emissions. ENGIE is already offering small industrialists using grey hydrogen an on-site production solution for renewable hydrogen (EffiH2 offer, developed by ENGIE Cofely).

Besides these uses, hydrogen could also in the future make the needs for heat of certain industries (steel, cement) greener.

Because hydrogen is used for all of these at the same time: balancing of the networks, greening of transport, industrial processes and heat production, it becomes the key to 100% renewable territories which harness the principles of the circular economy.

In which renewable electricity surpluses are converted into hydrogen, and then reinjected into the gas network, transformed into fuel, for heat production or reconverted into electricity. All of these at different scales: that of a building, an industrial site, an entire area.

What more does renewable hydrogen need to establish itself on a large scale?

Further work is needed on costs to improve the competitiveness of this energy vehicle. We need to work with the manufacturers of equipment such as electrolysers which are central to the hydrogen chain, in order to industrialise their production. We also need accompany changes to the regulations to boost the emergence of this sector.

Finally, and above all, we need to find the right economic models for using renewable hydrogen in transport, micro-networks, gas networks etc., in order to be able to scale up.

Despite these challenges I am very optimistic.

Because today, hydrogen is already an industrial reality.

Car makers such as Hyundai, Toyota and Renault are developing hydrogen vehicles. Buses and trucks are already running on hydrogen and refuelling in the hundreds of hydrogen stations that exist around the world.

Because many companies, such as our partners on the projects that we are developing (Renault, Symbio, Van Hool, ITM Power), or companies that are members of the Hydrogen Council (Air Liquide, Alstom, Bosch, Daimler, Total etc.) are organising themselves.

Because several countries have ambitious plans to expand the hydrogen sector and because the local level (city of Pau, urban community of Dunkirk) is moving in this direction.

This joint movement in favour of renewable hydrogen should enable us to make the quantum leap towards a totally decarbonised world, where technological innovation is harnessed to the benefit of all and to more harmonious progress.